Internal and forced climate variability from past climate changes to projections by Quentin Dalaiden

Louvain-La-Neuve

June 13, 2023

13h

BST 01

Climate variability includes an internal and forced component. Internal variability refers to the inherent fluctuations of the climate
that arise with the climate system itself. These fluctuations emerge from the interactions between the different components of the climate
system (e.g., atmosphere, ocean). One of the most known examples of internal variability is El-Ninõ-Southern Oscillation. On the other hand,
the forced variability arises from external factors of the climate system that influence the climate. These external forcings can be
natural, such as volcanic eruptions or orbital forcing, and anthropogenic, such as greenhouse gas emissions. Albeit internal
variability has no influence on the total radiative budget of the Earth (in contrast with the forced variability), internal variability can have
significant impacts on regional and global scales. Internal variability thus adds an element of inherent unpredictability to the climate system.
In this talk, we will discuss the processes behind these two components along with the consequences of internal variability on climate projections.